docs: def uri_from_fields(prefix, *fields):
          """Construct a URI out of the fields, concatenating them after removing offensive characters.
          When all the fields are empty, return empty"""
          string = '_'.join(AlignmentHelper.alpha_numeric(f.strip().lower(), '') for f in fields)
  
          if len(string) == len(fields) - 1:
              return ''
  
          return prefix + string